Zero Definition and 1000 Threads

Homework Statement Solve the BVP for a vibrating string with Separation of Variables/Fourier's method. \frac{\partial ^2}{\partial ^2 t} u(x,t) = c^2 \frac{\partial ^2}{\partial ^2 x} u(x,t) The string is of length L with each end fixed, ie u(0,t) = u(L,t) = 0 The Attempt at a Solution I...

is it possible to have zero velocity and zero acceleration for a moving object for example with trajectory x= (t-2)^3 at t=2 a=v=0

Homework Statement Wheatstone bridge. Homework Equations i Why the voltage across whetstone's bridge isn't always zero ? according to ohm's law . It must be zero (V=I*R, R=0) =>V=0 across the bridge . The Attempt at a Solution I think I'm missing something . the following sentence isn't...

Are there any elementary particles with zero intrinsic spin? Thanks in advance.

i have a simple question, but I'm not sure it can be answered with our knowledge of absolute zero: if an object were to exist at absolute zero, that means it has no energy, correct? if that is true, then if you struck something at absolute zero with another object, would the object with no...

when a sphere starts moving with initial velocity ##v_0## and zero angular velocity in a plane surface having friction, then first it will start rotating till it starts pure rolling. that is, its velocity of centre of mass will decrease due to backward friction and angular velocity will increase...

I've heard famous physicists like Stephen Hawking promote the idea that the conflict between the laws of thermodynamics and the beginning of the universe can be avoided if there is the same amount of anti-matter as there is matter, making the total energy level zero. I understand, that makes...

Homework Statement I want to integrate \int_0^e \ln(x) but first, I wondered if it would be divergent. I figured if xx goes to zero as x goes to zero then the integral would diverge (because xln(x)-x would diverge). 2. The attempt at a solution I'm wondering how you could show that this limit...

hi i am araz a mechanic master engineer and i am looking for any article or information about" Instantaneous Center of Zero Acceleration of Rigid Body" because i couldn't find any but "Instantaneous Center of Zero velocity":confused: i hope here i can find some help?!

Homework Statement Homework Equations https://www.physicsforums.com/attachments/upload_2015-1-15_18-57-56-png.77691/ Density matrix for a 2 state system is: https://www.physicsforums.com/attachments/upload_2015-1-15_19-1-30-png.77694/ The Attempt at a Solution For a 2 finite state...

hello there i kinda need help with this, image attached in the thread this is the ohmmmeter circuit and i have two questions : -what is the effect of R2 when it become lower than Rm? -what is the effect of R2 when it become higher than Rm? Rm=internal resistance of ohm-meter R2=zero adjust...

Hello, I received a copy of this newly published book for Christmas and I am about halfway thru it. It is a very interesting read so far with an incredible amount of information and it is highly referenced. Has only else read or is currently reading this book...

I have data from a pendulum and I am using it to work out the radius of the pendulum. I have acceleration in the x and y directions and so thought this would be easy enough. Simply I determine the (velocity in the x direction)^2/acceleration in the y direction. However when I use python to give...

hi, i have studied zero point energy as hf/2 , my question- is it present in cavity only? what is the value of f , does this value change with different atom-cavity system? thanks

I was thinking about the concept of the ground being the arbitrary zero potential point for gravitational potential energy and considered that since gravity is the attractive force between two objects that there would be no potential energy if an object's center of mass were somehow situated...

Alright so I'm still trying to get a hang of the theories of relativity, and this thing has really been bugging me. All forms of motion (and sometimes even physical observations) are defined for a particular local frame of reference. But is there any "stationary" frame of reference in the...

Hello, Is it possible to build a qubit from an atom with a nuclear spin of zero (ie. 16O, 12C, 32S)? Would it depend on electron spin instead? Thanks!

If Anna has 0 coins and Bertus has 0 coins aswell. Can you say that Anna has twice as much coins as Bertus? Because 2*0=0. But couldn`t you also say that Anna has four times more coins than Bertus, but simultaneously Bertus has 5 times more coins than Anna? Making it a paradox?

So I learned recently that pressure gradient in the flow direction for flow over a flat plate is zero. However I don't understand this, because there has to be something that sets the flow in motion in the first place, and for fluids this has to be a pressure gradient. Could someone explain why...

Why does hydroquinone possesses non zero dipole moment? The OH groups present at para positions on the benzene ring should cancel the effect of each other...if there is a plane change then exactly in which cases molecules do change planes?

Homework Statement I already searched for solution and i found similar one but I'm still confused. -In which point between Earth and Moon gravity field equals 0 if distance between moon and Earth is 60.3 * radius Earth and mass of the Earth is 81 * mass of the moon. Homework Equations...

Hello, I have this problem (warning: log of zero in one function) when i try to simulate one system which apparentely doesn't have any problem. in order to follow with my project i need to know how to change something parameters or whatever that is doing that my equation give me this mistake...

Homework Statement The gravitational field strength between two objects is the sum of two vectors pointing in opposite directions. Somewhere between the objects, the vectors will cancel, and the total force will be zero. Determine the location of zero force as a fraction of the distance r...

Homework Statement Hi, I've been having problems visualizing and interpreting a situation where there is zero potential in a point, equidistant, between two opposite charges. What is the significance of this? Here's a sample problem:Consider two point charges. One has a charge of +1 μC and the...

Consider the famous harmonic oscillator. Now imagine I use my freedom in choosing the origin for the potential and choose, instead of the usual thing, V(x)=\frac{1}{2}m \omega^2 x^2-\frac{1}{2} \hbar \omega , so the TISE becomes: -\frac{\hbar^2}{2m}\frac{d^2 \psi}{dx^2}+\frac 1 2 m\omega^2x^2...

Consider a potential well in 1 dimension defined by $$ V(x)= \begin{cases} +\infty &\text{if}& x<0 \text{ and } x>L\\ 0 &\text{if} &0\leq x\leq L \end{cases} $$ The probability to find the particle at any particular point x is zero. $$P(\{x\}) = \int_S \rho(x)\mathrm{d}x=0 ;\forall\; x \in...

So a question on my linear algebra homework asks for the dimensions of Nul(A) and Col(A). Let A = \begin{pmatrix} -4 & -3\\ -1 &4\\ -3& -7 \end{pmatrix} I row reduced the above matrix to \begin{pmatrix} 1 & 0\\ 0 & 1\\ \end{pmatrix} Now, the T.A. for my section told us that to find the...

Homework Statement I was working on a problem where I had been given a differential equation to be solved using separation of variables. Two coordinates: a time coordinate and a single spatial coordinate (1-D problem). Homework Equations The domain for the spatial part was [0, L]. Given...

Argument A ##∫ 0 dx = 0x + C = C## Argument B ##∫ 0 dx = ∫ (0)(1) dx = 0 ∫ 1 dx = 0(x+C) = 0## Discuss.

In many vortex's, the center has low pressure, from the center of a stirring cup of tea to the centere of a hurricane or storm system. I'm trying to crudely model how this might apply to the center of a spiral galaxy. If the behavior is similar, and the center has a low pressure void...

Doing some searching about the zero point energy of the vacuum I came up with an excerpt from Google books, Page 62 of...

In the integration of Force with respect to displacement (W=∫F.dx), is that true if the rate of change of displacement approaches to zero? My teacher said the one which approaches to zero is the rate of change of time. But If I arrange the formula, I will get F=dW/dx then F= lim Δx→0 ΔW/Δx...

This assignment is translated from another language, so some words be not be completely correct Homework Statement (Annual market rate might be yield to maturity?) Face value = 1000 Obligation----Condition----Payment profile----Maturity------Annual Coupon Rate-----Annual market rate...

Homework Statement Hi i've noticed that, J^{ab}P^c + J^{bc}P^a+J^{ca}P^b = 0 [ Since J^{ab}P^c + J^{bc}P^a+J^{ca}P^b = x^a\partial^b\partial^c -x^b\partial^a\partial^c + x^b\partial^c\partial^a-x^c\partial^b\partial^a+x^c\partial^a\partial^b-x^a\partial^c\partial^b = 0 ] Next, I tried it on...

Hey! :o Let $\mu$ be a Borel measure in $\mathbb{R}$ such that $\mu(I)\leq v^a(I)$ for each bounded interval $I$, where $a>1$. Show that $\mu=0$. Could you give some hints how to show this?? Do we maybe use the identity that for each rectangle R the outer measure of R is equal to the volume...

Homework Statement [/B] A charge of +2q (a) is placed at the origin and a second charge of -q (b) is placed at x = 3.0 cm. Where can a third charge +Q (c) be placed so that it experiences a zero net force?Homework Equations F = k(Q1)(Q2)/r^2 E = kQ/r^2 Quadratic?The Attempt at a Solution [/B]...

I'm not sure if this question fits here, but I've had trouble finding a good simple physics forum, so I signed up here :) I'm trying to think if the below wheel (image below) could allow for my push mower to have a zero or near zero turn radius. The edges of the wheel contour up (from the...

Hey! :o I have the following exercise.. Show that the $2$-dimensional Lebesgue measure of the graph of a continuous real function is zero. Could you give some hints what I could do?? (Wondering)

Hello comrades, Question A negative charge of 3.00 mC is 1.20m to the right of another negative charge of 2.00 mC. Calculate the point along the same line between the two charges where the net electric field will be zero. Formulas E=kq/r2 Attempt at Solving Well, I get as far as setting...

1. Problem Statement: The figure shows a cross-section view of a very long cylindrical cable. There is an outer tube made of copper, inner radius 2R, outer radius 4R. The inner copper wire has radius R and is concentric with the tube. The inner wire has charge density –2λ (per unit length)...

I'm relearning basic electricity concepts and I can't find an answer to a situation I've thought up. Imagine a cube with no enclosed charge and an electric field through it parallel to two of its faces. Guass's law says that the flux should be zero because there is no enclosed charge. Every...

I'm relearning basic electricity concepts and I can't find an answer to a situation I've thought up. Imagine a cube with no enclosed charge and an electric field through it parallel to two of its faces. Guass's law says that the flux should be zero because there is no enclosed charge. Every...

Hello! Given: g_{ρσ} = g_{μ\nu}\Lambda^{μ}_{ρ}\Lambda^{\nu}_{σ} equation (1) It was then mentioned to take the 00 entry of equation (1): So, it went like 1= \Lambda^{ρ}_{0}g_{ρσ}\Lambda^{σ}_{0} equation (2) then equation (2) was set equal to (\Lambda^{0}_{0})^{2} -...

Homework Statement Find the zero divisors and the units of the quotient ring ##\mathbb Z[X]/<X^3>## The attempt at a solution If ##a \in \mathbb Z[X]/<X^3>## is a zero divisor, then there is ##b \neq 0_I## such that ##ab=0_I##. I think that the elements ##a=X+<X^3>## and...

I do not really understand the big picture of gauss law. For what I know a conductor is a material where electrons can move freely, but I am reading my book and they show pictures where the protons are all right below the surface. My other question would be how can you describe the inside of a...

x + 0 = x x - 0 = x x(0) = 0 x(0) = undefined ...is this how you call it or is it no solution? x^0 = ? What is x raised to the zero power? square root of 0 = ? Not sure about this one either. If anyone knows of any other properties of zero I'm leaving out, please feel free to...

Hi All, This is from a classical mechanics problem, and I already 'solved' the problem, but I'm interested in why a certain term is set to zero. I think I understand the concept but just want to clarify. The problem is a table with a hole in it and two masses on a string, one mass is...

Just something I've been chewing on. Let's create a number line: [-3,-2,-1,0,1,2,3] In the number line, the values approach zero in the negative spectrum and then ascend from the positive spectrum. Yet, zero is consider the medium. Some argue that zero's purpose as a placeholder gives it no...

So I'm looking at the hessian of the Newtonian potential: \partial^2\phi / \partial x_i \partial x_j Using the fact that (assuming the mass is constant): F = m \cdot d^2 x / d t^2 = - \nabla \phi This implies: \partial^2\phi / \partial x_i \partial x_j = -m \cdot...

I ran a search and didn't see anything posted recently, at least, on the current thoughts behind the zero-energy universe idea. http://en.wikipedia.org/wiki/Zero-energy_universe I had a few questions about this: 1) What is the opinion of people on this site of the validity of this idea...